The Poria extract has tonic effect, as well as a smoothing effect on stomach disorder. According to the Chinese medicine, the Poria extract is classified as a tranquilizer and a uretic agent. In addition, the Poria extract is used as one of essential ingredients of the Chinese medicine prescription for vital activity. On the basis of researches and experiments, which have been conducted in recent years on the pharmacological effect of the Poria extract, it has been concluded that the Poria extract has a favorable effect on tumor prevention, and that the Poria extract is beneficial to immunity enhancement and gastrointestinal system of a person suffering from a chronic disease.
As exemplification, the Japan Patent Publication Numbers 55-111791 and 57-38794 disclose an extract which is obtained from the cultivated mycelia of Poria cocos (Schw) Wolf and is effective in tumor prevention. The Japan Patent Publication No. 55-111422 discloses an extract which is directly obtained from Poria cocos (Schw) Wolf for use in tumor prevention. The Japan Patent Publication No. 8-119864 discloses an extract which is obtained by extracting Poria cocos (Schw) Wolf with methanol. By separation, triterpene compounds such as lanostanes and secolanostanes are obtained from the extract and are used as anti-emetic agents. The Japan Patent Publication No. 9-025232 discloses triterpene compounds, which is obtained by extracting Poria cocos (Schw) Wolf with methanol. The compounds are useful as a tumor promotion-inhibiting agent. The Japan Patent Publication No. 9-176184 discloses an extract of Poria cocos (Schw) Wolf, which is then refined to produce triterpene compounds for use as an agent for inhibiting inflammation and tumor promotion.
The China Patent Publication No. 1008183 discloses a method of making a Poria extract containing triterpene compounds. The method involves extracting the Poria powder with an acidic alcohol, neutralizing the extract with a basic solution, concentrating the neutralized solution, adjusting the pH thereof to about 10 and filtering the solution, acidifying the filtrate to form a precipitate, washing the precipitate after filtration, and drying the washed precipitate. The Poria extract so obtained is found to have a tumor-preventive effect and an immunity activation effect.